Lock.



No. 704,!80. Patented July 8, i902.

A. B. FERGUSSON.

LUCK.

(Application filed Apr. 22, 1901.)

(No Model.) 2 Shegalw-Sheet I,

17222972607? CZZarzJZfZvywaon Patented July 8, I902. A. R. FERGUSSON.

L 0 C K.

(Application filed Apr. 22, 1901.)

2 Sheets-Sheet 2.

(No Mudei.)

five/2502? Q2422 592w azzome cc, wcrouwa. wAswm-ams, av c THE Noams armsUNITED STATES PATENT OFFICE.

ALAN ROBE FERGUSSON, OF NEXV YORK, N. Y.

LOCK.

SPECIFICATION forming part of Letters Patent No. 704,180, dated July 8,1902.

Application filed April 22, 1901. Serial No. 56,887. (No model.)

To all whom it may concern.-

Be it known that I, ALAN ROBE FERGUSSON, a citizen of the United States,residing in the borough of Manhattan, in the county of New York andState of New York, have invented certain new and useful Improvements inLocks,ofwhich the followingisaspecification.

This invention relates to looks, the object of the invention being toprovide an improved lock having automatically-operative means effectiveto lock the bolt or latch in its protracted or normal latching orlockingposition.

A further object of the invention is to provide a look mechanismextremely simple in construction and operation, free of complicatedparts or mechanisms,-inexpensive to manufacture, and which can be madeof comparatively small size, involving as one part thereof improvedmeans for automatically locking the latch or bolt in its workingposition.

In the drawings accompanying and forming part of this specification,Figure 1 is a transverse sectional view of a portion of a door and jambwith this improved lock mechanism in position and connected with theknobs of such door, the dotted lines representing the door partiallyopen. Fig. 2 is a side View of the organization shown in Fig. 1. Fig. 3is a sectional view of this improved lock mechanism and its casing.Figs. 4 and 5 are cross-sectional views of the mechanism, taken in linea a, Fig. 3, Fig. 4 showing a part of the lock-casing detached from thatpart thereof shown in Fig. 5. Fig. 6 is a crosssectional view of thelock mechanism partly in elevation, taken at right angles to Fig. 3.Figs. 7, 8, 9, 10, and 11 are detail views of various parts of thisimproved lock mechanism, all the parts of such lock mechanism beingshown except the springs for the bolts and the connecting device betweenthe main bolt and the hub of the knob. Fig. 12 is a crosssectional viewof a part of this lock mechanism,illustrating the bolt retracted bytheknob; and Fig. 13 is a similar view showing the locking devicereleased from the main bolt.

Similar characters of reference designate corresponding parts in thedifferent figu res in the drawings.

Since it is possible in the ordinary construction of looks or latches toinsert a knife or other thin instrument intermediate the jamb and thedoor and push back the latch or bolt, and so permit the door to beopened, it is desirable to provide means for preventing suchmanipulation, which means will be automatically operative on theshutting of the door and preferably by means of a device retracted andheld in its retracted position by the jamb.

I am aware that it is not new to provide an automatically-operativemeans to prevent the retraction of the bolt 0r latch by the insertion ofan implement between the jamb and the door; but all the mechanisms ofwhich I am aware adapted to accomplish this purpose are complicated,involving a large number of parts, and expensive to manufacture, it nothaving been found possible heretofore, so far as-I am aware, to providea simple lock mechanism comprising only a few parts in which the latch01' bolt will be automatically locked on the closing of the door, andtherefore the primary object of the present invention is to provide alock mechanism of this description.

This improved lock mechanism comprises, in a general way, a shiftablebolt or latch connected with the knob for movement thereby in onedirection, a locking device operative to engage said bolt and preventthe retraction thereof, and a shiftable device adapted to engage and beoperated by the jamb or other part on the doorway and when retracted topermit the locking of said bolt, the unlocking of such bolt beingeffected when the door is in its closed position by means of the knob,these few simple parts comprising the major part of the device and beingso organized that they can be readily assembled in a lock-casing ofcomparatively small size.

In one form thereof herein shown and do scribed the lock-casing is showncomprising a tubular or cylindrical casing 2, preferably closed at itsinner end and provided at its outer end with a face-plate 3 forattachment to the door. The casing may comprise a pair ofsemicylindrica'l members or plates at and 5, suitably securedtogether-as, for instance, by a screw or screws 6. The cas ing isprovided with a transverse opening 7 for the passage of the knob-spindle8, which projects through a hub 9, mounted to turn in such casing. Thishub is provided with a working part, such as a cam-face 10, for thepurpose hereinafter specified, and is connected bya suitable connector,shown herein as a chain 12, with the main bolt or latch 13 projectingthrough the face-plate, and which usually has a beveled end, such boltbeing supported in the present instance by a faceplate and by anapertured member or partition let within the casing. A suitable coiledspring 15 is located on the bolt-shank intermediate such partition andthe head of the bolt for maintaining such bolt in its protractedposition. The shank of this bolt is shown provided with a notch orrecess 16,

forming an oli'set, cooperating with which is a locking device,designated in the presentinstance as a tumbler l7, pivotallysecured to aprojection or pin 18, secured in the casing, which tumbler is shownprovided with a beveled end 19, complementary to the shape of the notch16: This member is so located that the working or cam face 10 of the hubis in position to raise it on the turning of the knob,it beingmaintained in engagementwith such working face and in its lockingposition by a suitable spring, shown herein as a flat spring 20. Forcontrolling the engagement of the tumbler with the main bolt or latch acontroller shown comprising a shiftable member is provided, which in theform shown comprises an auxiliary bolt 21, having a beveled face thehead of which projects through the face plate so as to engage thelockkeeper or jamb of a doorway, the shank being mounted in thepartition 14:. This bolt is located in such position that one bolt is infront of the other, the auxiliary bolt being shown located in the rearof the beveled side of the main bolt or latch. This auxiliary bolt ismaintained in its protracted position by means of a suitable coiledspring 22, located.

intermediate said partition and the head of the bolt. This bolt controlsa device adapted to interfere with the locking of the main bolt, whichdevice is shown comprising a laterallyextending member or arm 23,carried by the bolt and preferably having a beveled edge 24, adapted towork intermediate the locking device and. the main bolt, thereby tothrow or shift the locking device out of engagement with said main bolt.

In operation when the dooris pushed to, the main bolt is pushed in inthe usual manner until it is opposite the opening 25 in the keeper orstrike plate 26, when its coiled spring forces it into its protracted orlooking position. During this operation the auxiliary bolt has likewisebeen pushed in by the keeper or jamb of the doorway, so that its arm 23is shifted into position to permit the spring 20 to force the tumblerinto engagement with the notch in the main bolt, and so prevent theretraction of the main bolt as long as the' auxiliary bolt is held inits retracted position by the keeper or jamb of the doorway in a mannerwhich will be readily understood. When it is desired to open the door,the turning of the knob will throw the locking de vice out of engagementwith the main bolt, and so permit such bolt to be retracted. The turningof the knob will of course in practice be prevented in some suitablemanner -as, for instance, by providing a locking mechanism within theknob and operated by a key through such knob. Some suitable means mayalso be provided for locking the main bolt in its protracted positionfrom the inside of the door, so that the same cannot be retracted evenwhen the knob is turned.

From the foregoing it will be seen that the present improved lockmechanism comprises, in connection with a main bolt or latch present inall look mechanisms of this character and connected with the knob insome suitable manner, a spring-controlled locking device in the form ofa tumbler and a controller therefor, shown comprising aspring-controlled auxiliary bolt, which parts in the form shown comprisefour members-the auxiliary bolt having a laterally-extending arm, aspring therefor, a locking device, and a spring therefOr being soassembled that without the addition of other parts and by simply forminga notch in the main bolt and a cam-face on the knob-spindle hub the mainbolt can be automatically locked on the closing of the door, so that itcannot be opened by the insertion of a knife-blade or other thininstrument between the jamb and the door and unlocked by the turning ofthe knob.

Not only is the present mechanism simple in its organization andoperation, but the location of the bolts one in front of the otherprevents tampering with the rear or auxiliary bolt to effect theunlocking of the door. Were this auxiliary bolt located above or belowthe main latch it would be in such position that it could be tamperedwith. In the present case the main bolt or latch protects the auxiliarybolt, it being in front of the latter, so that the insertion of aknife-blade or cutting tool between the door and the jamb for thepurpose of forcing a hole in the jamb, so that the auxiliary bolt couldbe projected out ward by its spring, is not possible, since thiscutting-tool would have to first cut through or entirely remove the mainlatch, which is not a practicable operation. It will there fore be seenthat as the main latch is locked by mechanism located within the1ock,'which mechanism is in turn controlled by the auxiliary bolt, andwhich is located behind and protected by the main latch, it is not possible to manipulate the main latch surrepti tiously in any practicablemanner. Conse-' quently not only does the auxiliary bolt prevent theimproper working of the main latch, but the main latchin turn protectsthe auxiliary bolt in such manner that the lock mechanism cannot bemanipulated except by the proper means and in the proper manner.

I claim as my invention 1. In a lock, the combination of a pair of boltsor latches, one behind the other,- one a ICC main latch and the other anauxiliary member or bolt; a shiftable tumbler for engaging the bolt; andmeans carried by the auxiliary bolt and movable between the tumbler andmain latch for positively moving and holding the tumbler out ofengagement with the main latch when said auxiliary bolt is in itsprotracted position.

2. In a lock mechanism, the combination with a latch or bolt, of alocking-tumbler for locking said latch and comprising a pivoted leverhaving a flanged end; and an auxiliarybolthavingalaterally-extendingpartmovable between the flanged end ofsaid tumbler and the latch and effective When in its protracted positionto interfere With the locking of said latch by said tumbler, and whenshifted into a retracted position to permit the locking of said latch.

3. In a lock, the combination With a casing, of a knob-spindle carriedthereby having a tumbler-engaging surface; a pair of springcontrolledlatches or bolts, one behind the other, one a main latch connected withsaid spindle for movement thereby and the other an auxiliary bolt; aspring-controlled tumbler having a part adapted to engage said mainlatch and lock the latch in a protracted position, said auxiliary bolthaving a part movable between the tumbler and main latch for positivelymoving and holding the tumbler out of engagement with the main latchwhen said auxiliary bolt is in its protracted position, the organizationbeing such that on the rotation of the knob-spindle or the protractionof the auxiliary bolt the tumbler will be disengaged from the mainlatch.

4. In a lock mechanism, the combination With a tubular casing, of aknob-spindle projecting transversely thereof and carrying a cam; a mainbolt or latch carrying a spiral spring and connected with said spindleby a chain and havingastop-face; a tumbler pivotally connected to saidcasing at one side of the spindle and having a flanged end at the otherside of said spindle effective to engage the stop-face of said latch aspringfor throw ing said tumbler into locking position, the cam on theoperation of the knob being ef* fective to lift said tumbler from thelatch; an auxiliary bolt mounted in said casing and carrying a spiralspring, said bolt having a laterally-projecting part provided With abeveled end Working intermediate the flanged end of said tumbler and thelatch and effective in one position to permit the locking of said latchby the tumbler, and in another position to lift said tumbler free of thelatch.

ALAN ROBE FERGUSSON.

\Vitnesses:

O. A. WEED, GEO. N. SEARS.

